Neutrophil recruitment is a central component of inflammation, and there is intense focus on inhibiting the process both for chronic inflammatory disorders and for conditions where inflammation plays a contributory role, such as atherosclerosis. Chemotaxis - the movement of cells aligned with a chemical gradient - is the fundamental process underlying neutrophil recruitment. Despite its importance, screening tools for high throughput analysis of neutrophil recruitment are limited and there are none that allow quantitative measurement of cell chemotaxis in a defined gradient. Accordingly, the goal of this Phase I proposal is to develop a novel microfluidics device - called the Microfluidic Chemotaxis High Throughput System [unreadable]FCXHTS (Fig. 1) - for high throughput assays of neutrophil chemotaxis in a defined, stable chemical gradient. The project is a collaboration between Salus Discovery, a developer of microfluidic technology, and Dr. Anna Huttenlocher at the University of Wisconsin - Madison, who brings extensive experience in the molecular analysis of leukocyte chemotaxis. In preliminary studies, Dr. David Beebe - a scientific founder of Salus Discovery - and Dr. Huttenlocher developed the basic design for the static gradient chamber of the [unreadable]FCXHTS and validated a single-assay prototype device fabricated from elastomeric polymer. In Phase I, we will show feasibility for fabrication of a commercial [unreadable]FCXHTS device. The static gradient chamber will be incorporated into an array format, methods for fabrication from polystyrene will be developed, and the resulting [unreadable]FCXHTS will be validated for identification of compounds that inhibit neutrophil migration. The migration of cells from the bloodstream to sites of injury is one of the fundamental processes underlying chronic inflammatory disorders such as arthritis and inflammatory bowel disease. Responding cells migrate toward higher concentrations of signaling molecules that are released at the injury site. To enable the discovery of drugs to block this process, we are developing plastic devices for high throughput cell migration assays in defined chemical gradients. [unreadable] [unreadable] [unreadable]